The present invention relates to an apparatus for effectively photosynthesizing photosynthetic substances such as algae typified by chlorella or spirolina, photosynthetic bacteria or artificial photosynthetic substances such as callus.
Photosynthetic apparatuses heretofore proposed include an apparatus for culturing chlorella (unicellular microorganism containing chlorophyl). Difficulty experienced in culturing chlorella is that illumination with intensities higher than a certain level destroys the chlorophyl and produces a toxin (phaeophorbite) while illumination with intensities lower than a certain level fails to cause photosynthesis altogether. It is therefore a primary requisite for effective photo-synthesis that all the cells containing a photosynthetic substance be constantly supplied with light evenly distributed. Generally, organisms in a swarm increase not only their multiplying ability per unit volume but their resistance to other fungi. The culturing efficiency, therefore, grows poor unless a predetermined light radiating area per one liter of culture medium is ensured. With this in view, it has been customary to promote the transmission of light by reducing the number of individuals of a photosynthetic substance. This involves an inconsistency, however, because an increase in the number of individuals lowers the transmissibility to light and, therefore, requires collection of the individuals, but the resulting decrease in the number of individuals weakens the resistance to the fungi. Another drawback hitherto encountered is that the light intensity is excessively high for the individuals near a light source but is insufficient for those remote from the light source and, additionally, the light is absorbed by water to have its wavelength component varied. An ideal situation is, therefore, that a photosynthetic substance be passed through a very narrow clearance while a predetermined intensity of light is directed perpendicular to the clearance. Then, sufficient light will be evenly applied to all the cells containing the photosynthetic substance with a minimum of attenuation and without any change in its wavelength component.
A photosynthetic apparatus presently in use includes a number of fluorescent lamps arranged in a reaction bath (e.g. chlorella culturing bath) and causes a photosynthetic substance to flow through the spaces between the lamps. However, the use of fluorescent lamps renders the apparatus bulky, increases power consumption and requires an awkward measure against heat generation by the lamps.
While the even supply of a sufficient amount of carbon dioxide (CO.sub.2) all over the reaction bath is essential in attempting efficient photosynthesis, it has been quite difficult so far to fulfill such a condition.
Additionally, no effective means has been proposed for preventing contamination by the dead part of a photosynthetic substance or the like which tends to accumulate in various sections of a reaction bath.